title: Nano-organization of amylose-b-polystyrene block copolymer films doped with bipyridine.
abstract: This paper discusses the self-assembly of rod-coil amylose-b-polystyrene (Mal-b-PS) block copolymer thick and thin films. The nano-organization falls in an interdomain spacing d of about 10 nm, much smaller than flexible-flexible petrol block copolymer systems. Additionally, hydrogen-bonding interactions between carbohydrate rods (amylose) and 4',4-bipyridine (bipy) molecules induces phase transitions. Indeed, adding bipy in maltooctadecaose-block-polystyrene (Mal18-b-PS) copolymers results, at room temperature, in the formation of a lamellar phase having Mal18 bipy-rich nanodomains instead of hexagonal close-packed (HCP) of cylinders made of Mal18, whereas a coexistence of Mal7bipy-rich cylindrical and spherical nanodomains are formed from maltoheptaose-b-polystyrene (Mal7-b-PS) copolymers instead of a poorly organized array of Mal7-based cylinders. On heating, the Mal7bipy-b-PS system shows more rich phase behavior as compared to the Mal7-b-PS one due to weakening of hydrogen bonding with temperature. Such a system is of great interest in developing active layers in light-emitting diodes (LEDs) or in photovoltaic cells to realize devices with an optimal structure, that is, having large interface area and domain size with similar exciton diffusion length (10 nm).
authors.affiliation: Centre de Recherche sur les Macromolécules Végétales-CERMAV, CNRS UPR 5301-ICMG and Joseph Fourier University, BP53, 38041 Grenoble Cedex 9, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Aissou
authors.forename: Issei
authors.initials: I
authors.lastname: Otsuka
authors.forename: Cyrille
authors.initials: C
authors.lastname: Rochas
authors.forename: Sébastien
authors.initials: S
authors.lastname: Fort
authors.forename: Sami
authors.initials: S
authors.lastname: Halila
authors.forename: Redouane
authors.initials: R
authors.lastname: Borsali